Monolithic combustor for attritiable engine applications

ABSTRACT

A monolithic combustor apparatus comprises an outer casing comprising a forward flange, a fuel manifold disposed on the outer casing and defining an annular chamber extending perimetrically around the outer casing, a combustor liner disposed within the outer casing, the combustor liner defining an annular combustion chamber, a first annular plenum disposed between the outer casing and the combustor liner, an inner liner disposed radially from the combustor liner, a first inner flange extending forward from the combustor liner, and a second inner flange extending radially inward from the first inner flange.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of, and claims priority to, and thebenefit of, U.S. application Ser. No. 16/415,327, filed May 17, 2019 andentitled “MONOLITHIC COMBUSTOR FOR ATTRITIABLE ENGINE APPLICATIONS,”which is incorporated by reference herein in its entirety for allpurposes.

FIELD

The present disclosure relates to gas turbine engines, and, moreparticularly, to a combustor arrangement for a miniature gas turbineengine.

BACKGROUND

Miniature gas turbine or turbojet engines (typically of 150 foot pounds(lbf) thrust and smaller) are often utilized in single usageapplications such as drones and other small aircraft applications. Theuse of such an engine greatly extends the range of the aircraft incomparison to a solid fuel engine.

To achieve economically feasible extended range expendable propulsionsources for such applications, miniature gas turbine engines should beable to be manufactured relatively inexpensively yet provide a highdegree of starting and operational reliability.

SUMMARY

A monolithic apparatus is disclosed, comprising an outer casingcomprising a forward flange, a fuel manifold disposed on the outercasing and defining an annular chamber extending perimetrically aroundthe outer casing, a combustor liner disposed within the outer casing,the combustor liner defining an annular combustion chamber, a firstannular plenum disposed between the outer casing and the combustorliner, an inner liner disposed radially from the combustor liner, afirst inner flange extending forward from the combustor liner, and asecond inner flange extending radially inward from the first innerflange.

In various embodiments, the monolithic apparatus further comprises aninjector port extending into the combustion chamber from the combustorliner.

In various embodiments, the injector port defines a diamond-shapedaperture.

In various embodiments, the monolithic apparatus further comprises agusset extending from a forward edge of the injector port.

In various embodiments, an aft wall of the outer casing extends towardsthe inner liner at an angle with respect to a centerline axis, whereinthe angle is between thirty and eighty degrees.

In various embodiments, an aft, radially inner corner of the combustorliner comprises a chamfer.

In various embodiments, the monolithic apparatus further comprises adiffuser disposed at an inlet of the first annular plenum.

In various embodiments, the monolithic apparatus further comprises aturbine nozzle disposed at an exit of the combustion chamber.

In various embodiments, the monolithic apparatus further comprises asecond annular plenum disposed between the inner liner and thecombustion chamber.

A turbine engine arrangement is disclosed, comprising a forward housing,a rotor shaft rotatably mounted to the forward housing, a compressorwheel operatively coupled to the rotor shaft, a turbine wheeloperatively coupled to the rotor shaft, and a monolithic combustor. Themonolithic combustor comprises an outer casing comprising a forwardflange, wherein the forward housing is coupled to the monolithiccombustor at the forward flange, a fuel manifold disposed on the outercasing and defining an annular chamber extending perimetrically aroundthe outer casing, a combustor liner disposed within the outer casing,the combustor liner defining an annular combustion chamber, a firstannular plenum disposed between the outer casing and the combustorliner, an inner liner disposed radially from the combustor liner, afirst inner flange extending forward from the combustor liner, and asecond inner flange extending radially inward from the first innerflange.

In various embodiments, the turbine engine arrangement further comprisesan injector port extending into the combustion chamber from thecombustor liner.

In various embodiments, the turbine engine arrangement further comprisesa diffuser disposed at an inlet of the first annular plenum, wherein thediffuser receives a flow of air from the compressor wheel.

In various embodiments, the turbine engine arrangement further comprisesa turbine nozzle disposed at an exit of the combustion chamber, whereinthe turbine nozzle directs a flow of combustion gas towards the turbinewheel.

In various embodiments, a geometry of the first inner flange iscomplementary to that of the compressor wheel.

In various embodiments, a geometry of the second inner flange iscomplementary to that of the turbine wheel.

In various embodiments, the turbine engine arrangement further comprisesa second annular plenum disposed between the inner liner and thecombustion chamber.

In various embodiments, the turbine wheel extends at least partiallyinto the inner liner.

In various embodiments, the monolithic combustor is configured to directa flow of air in a first longitudinal direction through the firstannular plenum, in a second longitudinal direction through thecombustion chamber, and in the first longitudinal direction through theinner liner.

A method is disclosed, comprising defining a monolithic apparatus designhaving an outer casing comprising a forward flange, a fuel manifolddisposed on the outer casing and defining an annular chamber extendingperimetrically around the outer casing, a combustor liner disposedwithin the outer casing, the combustor liner defining an annularcombustion chamber, a first annular plenum disposed between the outercasing and the combustor liner, an inner liner disposed radially fromthe combustor liner, a first inner flange extending forward from thecombustor liner, and a second inner flange extending radially inwardfrom the first inner flange, and manufacturing a monolithic apparatusbased on the monolithic apparatus design using an additive manufacturingprocess.

In various embodiments, the monolithic apparatus design furthercomprises a diffuser disposed at an inlet of the first annular plenumand a turbine nozzle disposed at an exit of the combustion chamber.

The foregoing features and elements may be combined in variouscombinations without exclusivity, unless expressly indicated otherwise.These features and elements as well as the operation thereof will becomemore apparent in light of the following description and the accompanyingdrawings. It should be understood, however, the following descriptionand drawings are intended to be exemplary in nature and non-limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter of the present disclosure is particularly pointed outand distinctly claimed in the concluding portion of the specification. Amore complete understanding of the present disclosure, however, may bestbe obtained by referring to the detailed description and claims whenconsidered in connection with the figures, wherein like numerals denotelike elements.

FIG. 1 illustrates a schematic view of a vehicle with a miniature gasturbine engine, in accordance with various embodiments;

FIG. 2 illustrates a cross-sectional view of a miniature gas turbineengine, in accordance with various embodiments;

FIG. 3A illustrates a perspective view of a monolithic combustor, inaccordance with various embodiments;

FIG. 3B illustrates a section, perspective view of the monolithiccombustor of FIG. 3A, in accordance with various embodiments;

FIG. 3C illustrates a section, side view of the monolithic combustor ofFIG. 3A, in accordance with various embodiments; and

FIG. 4 illustrates a flow chart for a method for manufacturing amonolithic combustor, in accordance with various embodiments.

DETAILED DESCRIPTION

All ranges and ratio limits disclosed herein may be combined. It is tobe understood that unless specifically stated otherwise, references to“a,” “an,” and/or “the” may include one or more than one and thatreference to an item in the singular may also include the item in theplural.

The detailed description of various embodiments herein makes referenceto the accompanying drawings, which show various embodiments by way ofillustration. While these various embodiments are described insufficient detail to enable those skilled in the art to practice thedisclosure, it should be understood that other embodiments may berealized and that logical, chemical, and mechanical changes may be madewithout departing from the spirit and scope of the disclosure. Thus, thedetailed description herein is presented for purposes of illustrationonly and not of limitation. For example, the steps recited in any of themethod or process descriptions may be executed in any order and are notnecessarily limited to the order presented. Furthermore, any referenceto singular includes plural embodiments, and any reference to more thanone component or step may include a singular embodiment or step. Also,any reference to attached, fixed, connected, or the like may includepermanent, removable, temporary, partial, full, and/or any otherpossible attachment option. Additionally, any reference to withoutcontact (or similar phrases) may also include reduced contact or minimalcontact. Cross hatching lines may be used throughout the figures todenote different parts but not necessarily to denote the same ordifferent materials.

As used herein, “aft” refers to the direction associated with the tail(e.g., the back end) of an aircraft, or generally, to the direction ofexhaust of the gas turbine engine. As used herein, “forward” refers tothe direction associated with the nose (e.g., the front end) of anaircraft, or generally, to the direction of flight or motion.

As used herein, “distal” refers to the direction radially outward, orgenerally, away from the axis of rotation of a turbine engine. As usedherein, “proximal” refers to a direction radially inward, or generally,towards the axis of rotation of a turbine engine.

A one-piece, monolithic combustor of the present disclosure may be builtas a single part in the longitudinal direction using additivemanufacturing methods without a support structure. A geometry of themonolithic combustor of the present disclosure may be configured forefficient additive manufacturing, in accordance with variousembodiments. A monolithic combustor of the present disclosure may resultin reduced overall part count of a gas turbine engine, reduced overallweight of the gas turbine engine, reduced manufacturing time of the gasturbine engine, and/or reduced manufacturing time of the combustoritself.

FIG. 1 illustrates a general schematic view of a vehicle 100 including aminiature gas turbine engine 10 according to the present disclosure. Thevehicle 100 includes a body 102 and one or more aerodynamic surfaces104. The engine 10 is coupled to, or within, the body 102. A vehicleinlet duct 106 provides air to the engine 10, and an exhaust duct 108exhausts the thrust therefrom. The various components are shown in aparticular configuration for clarity, however other configurations arepossible in other embodiments such as, for example, in other singleusage and reusable applications such as drones and other small aircraftapplications.

With reference to FIG. 2 , the miniature gas turbine engine 10 generallyincludes a forward housing 14, a rotor shaft 16 rotationally mounted toforward housing 14, a compressor wheel 18, and a one-piece combustor 40.Rotor shaft 16 may be rotationally mounted to forward housing 14 via aforward bearing 21 and an aft bearing 22. The rotor shaft 16 rotatesabout a longitudinal axis X.

In the illustrated rotor configuration, a rotor system 24 includes amultiple of compressor blades facing forward toward an intake 28 todefine compressor wheel 18 and a multiple of turbine blades facingrearward toward the exhaust duct 92 to define a turbine wheel 30. Therotor shaft 16 is received in the bearings 21 and 22. In variousembodiments, the forward cover 25 of the inlet cone 23 is the forwardmost portion of the engine 10 and defines an aerodynamically contouredshape which facilitates the delivery of undistorted, primary airflow tothe intake 28.

In various embodiments, combustor 40 includes a forward flange 61whereby combustor 40 is coupled to forward housing 14. In variousembodiments, forward flange 61 may have a plurality of circumferentiallydisposed apertures extending longitudinally through forward flange 61whereby forward flange 61 is fastened to forward housing 14. In variousembodiments, forward flange 61 is fastened to forward housing 14 via aplurality of threaded fasteners.

In various embodiments, other components, such as a permanent magnetgenerator (PMG) for example, are mounted to the rotor shaft 16 behindthe forward bearing 21 to generate electrical power for the engine 10and other accessories. For example, a PMG may include a stator mountedwithin a forward housing inner support of the forward housing 14 and arotor mounted to the rotor shaft 16. One or mores electrical power wiresmay communicate electrical power from the PMG to an electrical powersystem.

In various embodiments, a fuel pump (illustrated schematically at 72)may be driven by an electrical power system to communicate fuel from asource to an annular combustor liner 46 through a fuel manifold 52.Combustor liner 46 may define an annular combustion chamber 47. One ormore ignitor holding features 49 (see FIG. 3B) may be disposed at an aftend of the combustor liner 46 for attaching one or more ignitors, suchas a torch, to combustor 40 whereby the fuel-air mixture is ignited. Thefuel is burned at high temperatures within the combustor liner 46 suchthat the expanding exhaust gases therefrom are communicated to theturbine wheel 30. The combustor liner 46 is in fluid communication withthe exhaust duct 92 such that exhaust gases from the combustor liner 46are directed through a turbine nozzle 44, through to the turbine wheel30, through the exhaust duct 92 and exiting the exhaust duct 108 (seeFIG. 1 ) of the vehicle for generating thrust.

In various embodiments, combustor 40 generally comprises an outer casing60, the combustor liner 46, a diffuser 42, a turbine nozzle 44, and aninner liner 48. In various embodiments, the combustor liner 46 isdisposed within outer casing 60 and forms an annular plenum 81therebetween. The diffuser 42 may be disposed at an inlet of plenum 81.An inner flange 62 (also referred to herein as a first inner flange) mayextend forward from combustor liner 46. Air may enter combustor 40 fromcompressor wheel 18 at inner flange 62. In this regard, the geometry ofinner flange 62 may be complementary to that of compressor wheel 18. Invarious embodiments, the inner flange 62 interfaces with the compressorwheel 18. The diffuser 42 may comprise a plurality of vanes 64 disposedcircumferentially around the inlet of plenum 81 and extending betweenouter casing 60 and inner flange 62. The plurality of vanes 64 may beconfigured to turn the air flowing entering plenum 81 to flowsubstantially parallel with the centerline axis X during operation. Theturbine nozzle 44 may be disposed at a forward end of the combustionchamber whereby exhaust gasses exit the combustion chamber 47 and expandacross the turbine wheel 30, thereby converting the thermal energy ofthe exhaust gasses into rotational movement energy of rotor shaft 16. Invarious embodiments, the turbine nozzle 44 is coupled to the inner linervia a forward, annular nose lip 65. The forward, annular nose lip 65 maycomprise a “C”-shaped cross-section geometry. The forward, annular noselip 65 may comprise a rounded, smooth, forward edge surface whereby thecombustion gas is turned into the inner liner from the turbine nozzle.

In various embodiments, an inner flange 63 (also referred to herein as asecond inner flange) may extend radially inward from inner flange 62.Inner flange 63 may direct the exhaust gases exiting turbine nozzle 44towards turbine wheel 30. In this regard, the geometry of inner flange63 may be complementary to that of turbine wheel 30. In variousembodiments, inner flange 63 interfaces with turbine wheel 30. Theturbine wheel 30 may extend at least partially into the inner liner 48.

In various embodiments, one or more fuel injectors 53 extend radiallyinward from fuel manifold 52 whereby fuel is injected into combustor 40.A fuel line attachment member 54 may extend from fuel manifold 52whereby fuel manifold 52 is supplied with the fuel from a fuel source.Fuel manifold 52 may define an annular chamber extending around theperimeter of outer casing 60 whereby fuel may be routed through outercasing at one or more location disposed circumferentially around outercasing 60. In this manner, the fuel manifold 52 may be integrated intothe outer casing 60. The atomized fuel may mix with air located withincombustor 40 upon entry thereof. A plurality of injector ports 56 mayextend radially inward from combustor liner 46 whereby the fuel-airmixture enters the combustion chamber 47. The fuel-air mixture mayignite in the combustion chamber 47, generating exhaust gases whichexpand through turbine nozzle 44, across the turbine wheel 30, and intoinner liner 48. In various embodiments, inner liner 48 defines anexhaust duct through which exhaust gases exit combustor 40. The turbinenozzle 44 comprises a plurality of vanes extending between forwardflange 62 and inner liner 48 and at least partially defining a flow pathfrom combustion chamber 47 to inner liner 48.

In various embodiments, during operation, combustor 40 receivescompressed air, illustrated by arrows 96, from the compressor wheel 18at the diffuser 42. The air entering diffuser 42 flows in acircumferential direction and is turned by plurality of vanes 64 to flowessentially aft-ward. The air 96 may enter combustion chamber 47 viainjector ports 56 whereby the air 96 mixes with fuel injected from theone or more fuel injectors 53. The fuel-air mixture may be ignited incombustion chamber 47 and the exhaust gasses may exit the combustionchamber 47 via the turbine nozzle 44 whereby the flow of exhaust gassesis turned, or swirled, in a circumferential direction for expandingacross turbine wheel 30. The exhaust gasses impart a rotational force onturbine wheel 30, thereby rotating compressor wheel 18, and enter theinner liner 48 whereby the gasses are exhausted from combustor 40 viaexhaust duct 92. In this regard, the flow of the air through combustor40, as illustrated by arrows 96, is directed in the aft direction (alsoreferred to herein as a first longitudinal direction) through plenum 81,directed radially inward (also referred to herein as a first radialdirection) through injector ports 56, directed in the forward direction(also referred to herein as a second longitudinal direction) throughcombustion chamber 47, directed radially inward from turbine nozzle 44into inner liner 48, and directed in the aft direction through innerliner 48 to an exit thereof.

Furthermore, as illustrated by arrows 96, the flow of air may flow aftward around the distal side of the combustor liner 46, around the aftend of the combustor liner radially inward, and in the forward directionalong the proximal side of the combustor liner 46, and through one ormore discrete standoff apertures 50 disposed circumferentially betweencombustor liner 46 and inner liner 48. Standoff apertures 50 may besized to meter the flow of air, illustrated by arrows 96, into thecombustion chamber 47. In this regard, each of the standoff apertures 50may be disposed between a plurality of turbine nozzle standoffs 51extending between, and integrated with, the combustor liner 46 and innerliner 48.

With combined reference to FIG. 3A, FIG. 3B, and FIG. 3C, combustor 40may be made from a metallic material suitable to withstand hightemperature gasses of the engine 10 (see FIG. 1 ). In variousembodiments, combustor 40 may comprise one of a nickel alloy, a nickelsteel (e.g., an austenitic nickel-chromium-based alloy such as thatavailable under the trade name INCONEL), or any other material suitableto withstand high temperature gasses of combustor 40.

In various embodiments, combustor 40 is additively manufactured. As usedherein, the term “additive manufacturing” encompasses any method orprocess whereby a three-dimensional object is produced by creation of asubstrate or material to an object, such as by addition of successivelayers of a material to an object to produce a manufactured producthaving an increased mass or bulk at the end of the additivemanufacturing process than the beginning of the process. In contrast,traditional manufacturing (e.g., forms of subtractive manufacturing) bymachining or tooling typically relies on material removal or subtractiveprocesses, such as cutting, lathing, drilling, grinding, and/or thelike, to produce a final manufactured object that has a decreased massor bulk relative to the starting workpiece. Other traditionalmanufacturing methods includes forging or casting, such as investmentcasting, which utilizes the steps of creating a form, making a mold ofthe form, and casting or forging a material (such as metal) using themold. As used herein, the term “additive manufacturing” should not beconstrued to encompass fabrication or joining of previously formedobjects.

A variety of additive manufacturing technologies are commerciallyavailable. Such technologies include, for example, fused depositionmodeling, polyjet 3D printing, electron beam freeform fabrication,direct metal laser sintering, electron-beam melting, selective lasermelting, selective heat sintering, selective laser sintering,stereolithography, multiphoton photopolymerization, and digital lightprocessing. These technologies may use a variety of materials assubstrates for an additive manufacturing process, including variousplastics and polymers, metals and metal alloys, ceramic materials, metalclays, organic materials, and the like. Any method of additivemanufacturing and associated compatible materials, whether presentlyavailable or yet to be developed, are intended to be included within thescope of the present disclosure. In this regard, combustor 40 is amonolithic structure, in accordance with various embodiments.

In various embodiments, the injector ports 56 may define adiamond-shaped aperture 312. The geometry of the injector ports 56 mayaid in the additive manufacturing process of combustor 40. In variousembodiments, each injector port 56 may include a gusset 314 extendingfrom a forward edge of the associated injector port 56 for aiding theadditive manufacturing process of injector port 56. The direction thatgusset 314 extends with respect to injector port 56 may depend on thedirection that combustor 40 is built during the additive manufacturingprocess.

In various embodiments, an aft wall 66 of outer casing 60 may extendradially inward towards inner liner 48 at an angle α with respect tocenterline axis X. In various embodiments, angle α is between twenty andninety degrees (20°-89°). In various embodiments, angle α is betweenthirty and eighty degrees (30°-80°). In various embodiments, angle α isbetween thirty and seventy degrees (30°-70°). Aft wall 66 may comprise atruncated cone. The aft wall 66 may extend linearly between outer casing60 and inner liner 48. The geometry of aft wall 66 may aid in theadditive manufacturing process. In various embodiments, the aft, innercorner of combustor liner 46 may be chamfered to aid in turning the flowof air in the forward direction. In this regard, air may flow aroundcombustor liner 46, in an aft direction between outer casing 60 andcombustor liner 46, in a radially inward direction between combustorliner 46 and aft wall 66, and may turn at the chamfer 67 to flow forwardbetween combustor liner 46 and inner liner 48. In this regard, anannular plenum 82 may be disposed between inner liner 48 and combustorliner 46.

In various embodiments and with reference to FIG. 4 , a method 400 formanufacturing a monolithic combustor using additive manufacturing caninclude defining a monolithic combustor design (step 410). For example,step 410 can comprise utilizing two-dimensional or three-dimensionalmodeling techniques to create a monolithic combustor design having atleast one of: improved dynamic stability, tuned stiffness, reducedweight, improved aerodynamic performance, tuned thermal efficiency,improved manufacturability, and improved vibration damping. For example,the monolithic combustor design of step 410 can include geometricattributes such as forward flange 61, inner flange 62, gussets 314,geometric apertures 312, angled walls 66, among others.

In various embodiments, the monolithic combustor design of step 410 isthen manufactured using an additive manufacturing process (step 420).For example, step 420 can comprise using a technique such as directlaser sintering to manufacture a monolithic combustor, such as combustor40, having the same geometry and configuration as the monolithiccombustor design of step 410.

Benefits and other advantages have been described herein with regard tospecific embodiments. Furthermore, the connecting lines shown in thevarious figures contained herein are intended to represent exemplaryfunctional relationships and/or physical couplings between the variouselements. It should be noted that many alternative or additionalfunctional relationships or physical connections may be present in apractical system. However, the benefits, advantages, and any elementsthat may cause any benefit or advantage to occur or become morepronounced are not to be construed as critical, required, or essentialfeatures or elements of the disclosure. The scope of the disclosure isaccordingly to be limited by nothing other than the appended claims, inwhich reference to an element in the singular is not intended to mean“one and only one” unless explicitly so stated, but rather “one ormore.” Moreover, where a phrase similar to “at least one of A, B, or C”is used in the claims, it is intended that the phrase be interpreted tomean that A alone may be present in an embodiment, B alone may bepresent in an embodiment, C alone may be present in an embodiment, orthat any combination of the elements A, B and C may be present in asingle embodiment; for example, A and B, A and C, B and C, or A and Band C.

Systems, methods and apparatus are provided herein. In the detaileddescription herein, references to “various embodiments”, “oneembodiment”, “an embodiment”, “an example embodiment”, etc., indicatethat the embodiment described may include a particular feature,structure, or characteristic, but every embodiment may not necessarilyinclude the particular feature, structure, or characteristic. Moreover,such phrases are not necessarily referring to the same embodiment.Further, when a particular feature, structure, or characteristic isdescribed in connection with an embodiment, it is submitted that it iswithin the knowledge of one skilled in the art to affect such feature,structure, or characteristic in connection with other embodimentswhether or not explicitly described. After reading the description, itwill be apparent to one skilled in the relevant art(s) how to implementthe disclosure in alternative embodiments.

Furthermore, no element, component, or method step in the presentdisclosure is intended to be dedicated to the public regardless ofwhether the element, component, or method step is explicitly recited inthe claims. No claim element is intended to invoke 35 U.S.C. 112(f)unless the element is expressly recited using the phrase “means for.” Asused herein, the terms “comprises”, “comprising”, or any other variationthereof, are intended to cover a non-exclusive inclusion, such that aprocess, method, article, or apparatus that comprises a list of elementsdoes not include only those elements but may include other elements notexpressly listed or inherent to such process, method, article, orapparatus.

What is claimed is:
 1. A method, comprising: defining a monolithicapparatus design comprising an outer casing comprising a forward flange,a fuel manifold disposed on the outer casing and defining an annularchamber extending perimetrically around the outer casing, a combustorliner disposed within the outer casing, the combustor liner defining anannular combustion chamber, a first annular plenum disposed between theouter casing and the combustor liner, wherein the fuel manifold isdisposed radially outward from the first annular plenum, an inner linerdisposed radially from the combustor liner, a first inner flangeextending forward from the combustor liner, and a second inner flangeextending radially inward from the first inner flange, and an aft wallof the outer casing at least partially defining a flow path for a flowof air around the combustor liner, wherein the aft wall extends from theinner liner at an angle with respect to a centerline axis of themonolithic apparatus; and manufacturing a monolithic apparatus based onthe monolithic apparatus design using an additive manufacturing process.2. The method of claim 1, further comprising defining the monolithicapparatus design to further comprise a diffuser disposed at an inlet ofthe first annular plenum.
 3. The method of claim 2, further comprisingdefining the monolithic apparatus design to further comprise a turbinenozzle disposed at an exit of the annular combustion chamber.
 4. Themethod of claim 1, further comprising defining the monolithic apparatusdesign to further comprise an injector port extending into the annularcombustion chamber from the combustor liner.
 5. The method of claim 4,further comprising defining the monolithic apparatus design to furthercomprise a gusset extending from a forward edge of the injector port. 6.The method of claim 5, further comprising defining the monolithicapparatus design to further comprise a fuel injector aligned with theinjector port and configured to direct a fuel from the fuel manifold tothe injector port.
 7. The method of claim 4, wherein the injector portdefines a diamond-shaped aperture.
 8. The method of claim 1, wherein theangle is between thirty and eighty degrees.
 9. The method of claim 1,further comprising defining the monolithic apparatus design to furthercomprise a second annular plenum disposed between the inner liner andthe annular combustion chamber.